a) Field of the Invention
The invention relates to a can-filter structure of oxygen concentrator and, more particularly, to a can-filter structure of household or personal PSA oxygen concentrator.
b) Description of the Related Art
An oxygen concentrator provides oxygen at substantially higher concentrations than those of ambient air. The oxygen concentration in general ambient air is around 20%, but it would help a person to recover from tiredness and release pressure after high-intensity exercises if the oxygen concentration is raised to about 30% to 35%. Moreover, patients with respiratory problems like asthma need highly concentrated oxygen for medical and heath care purposes.
Common methods used to supply oxygen include: 1) pressure swing adsorption (PSA), 2) electrolysis, and 3) usage of oxygen tank. The PSA method is to obtain oxygen from ambient air, wherein through the work of a molecular sieve in the oxygen concentrator, nitrogen in the ambient air is absorbed, and thus the effect of continuously obtaining oxygen from air is achieved. The electrolysis method is to generate oxygen and hydrogen by liquid water electrolysis, and the oxygen is extracted for use. The oxygen tank is a steel cylinder, in which oxygen is stored in liquid state and under high pressure, and oxygen is released from the tank when it is needed.
In terms of the PSA oxygen concentrator, since the can-filter and molecular sieve are used to carry out oxygen generation, they are required to be replaced periodically. However, due to the complexity of the internal assembly, most of the replacement and disassembling operations are performed by professional technicians, which is very inconvenient to the users. Moreover, most of the oxygen concentrators are bulky in size and are unsuitable for use in automobiles or as portable devices.
According to prior art, in a PSA oxygen concentrator, two can-filters to be coupled are provided with inner threaded portion and outer threaded portion, respectively, at the corresponding connection portions thereof, and sealing tapes are attached to the threaded portions. Then, two can-filters are coupled by screwing together their corresponding threaded portions with sealing tapes being sandwiched therebetween. This operation process is complicated and results in poor air tightness, which is prone to air leakage.
In addition, conventionally, the outlet of the second can-filter in PSA oxygen generators is a straight round pipe, but such design would cause a hose, which is used to connect between the pipe and other devices, to deform at turns. The deformation of hose would block airflow, making the air to flow not as smoothly or the local pressure to be high, and in turn causes air leakage or damages to the elements. Furthermore, the hose used for connection has to be detached when replacing can-filters, thus it is very inconvenient to use.
For household or personal oxygen concentrators, safety, convenience, and reasonable pricing are important considerations. The invention is a design that made a structural improvement to PSA oxygen generators, making them more compact, lightweight, and easier to assemble and replace consumables/materials. In other words, the invention has a competitive price and is more suitable for household or personal use.